This invention relates generally to electricity metering, and more particularly, to a microcomputer based electricity meter.
Electronic electricity meters for metering multi-phase services typically include a digital signal processor (DSP) and a microcomputer. Certain functions and operations are separately performed in the DSP and microcomputer. By dividing the functionality between the DSP and microcomputer, communications of data and commands must be provided between the DSP and microcomputer. Such an architecture is complex.
In addition, such meters typically are programmed to perform certain functions. Although the meters are upgradeable, the types of upgrades that can be performed are limited to the tables and functions prestored in the meter. In addition, and in the past, increased functionality typically was a trade-off to cost. That is, adding functionality to the meter typically resulted in adding significant costs to the meter.
It would therefore be desirable to provide methods and apparatus for electricity metering that do not require a DSP as well as a microcomputer, and that provide the flexibility of increased functionality by program upgrades.
There is therefore provided, in one embodiment of the present invention, a method for measuring electricity usage that includes steps of: coupling a sensor to a power source; converting a signal from the sensor to a digital measurement signal; using a microcomputer to determine quantities indicative of electricity consumption from the digital measurement signal; and using a nonvolatile, reprogrammable memory coupled to the microcomputer to control the microcomputer in determining the quantities indicative of electricity consumption.
The above-described embodiment performs metering of electricity usage without requiring a DSP. In addition, reprogrammability is provided so that metering upgrades are easily performed.